Internal-combustion engine



May 6, 1930. c, MEHLUM 1,757,778

INTERNAL COMBUSTION ENGINE Filed Feb. 24, 1927 "been May 6, 1930 UNITED STATES. PATENT OFFICE CASPER EEHLUM, 0F WAL'LHAM, MASSACHUSETTS INTERNAL-COMBUSTION ENGINE Application filed February 24, 1927. semi No. 170,623.

The invention relates to an improvement in internal combustion engines. It relates especlally to an engine in which aplurality of pistons have driving connection with a cam mounted on a rotary shaft whereby the recip into rotary'm'ovement of the shaft; The invention relates especially to the driving connections between the pistons and the cam-carried by the shaft. The main feature of the invention consists in forming the cam in two sections inaxial relation to each other and spaced apart and providing each piston rod With branches carrying a stud on which two cam rolls are disposed on an axis at right angles to the piston rod, one of said cam rolls being adapted for engagement with one of said cam sections and the other of which is adapted to engage with the other of the grouped 90 apart around a. vertical rotary as fcam shaft 22 ]ournalled in bearings 24, 25,.

Two of the cylinders are not shown by reason of the view being in section. Each piston is mounted on a rod 28 bifurcated at its lower end. 1

Mounted on the shaft 22 is a c lindrical cam formed in twosections 7 0' and I1 axially disposed with relation to each other. The two sections are secured together by bolts 72 or The lower edge of other suitable means. the upper section 70 is-formed with a cam surface'73 and the upper edge of the lower secv tion 71 is formed with a cam surface 74. A

stud 7 5 projecting from each piston rod 28 v carries two rolls 7 6 and 7 7, the roll 77 being between the branches of the fork. The roll 76 rocating movement of the pistons is converted is always in engagement with the upper cam surface 73 and the roll 7 7 is always in engagement with the lower cam surface 74. There is a clearance as shown at 78 between the cam roll 76 and the lower cam section 71 and there is a clearance between the cam roll 77 and'the upper cam section 70. 'It will be seeen, therefore, that there will beno'cross over of either cam roll from one cam section to the other, and the movement will be smooth and steady and free from undue friction. p v

The bolts 72 are adjustableto regulate the space between the cam sections and to permit adjustment of said sections with relation to each other to takeupywear and to niaintain the properbearing engagement of the rolls with the cam surfaces. 1

'VVhile I have described myiinvention as embodied .in a motor of the four cylinder type, I do not limit myself to this construc tion as the number of cylinders is immaterial and may be increased or decreased according to the type desired.

What I claim is:

In combination with a cylinder, its piston and piston rod, two cam members mounted-in axial alinement with each other and,

spaced apart fromeaoh other, the operative faces of said two cams facing in opposite directions to each other, said piston rod being forked at its outer end, a stud passing" through the branches of said fork and extending beyond one .of said branches, a cam roll mounted on that portion of the said stud which is'bet'ween said branches, a second cam roll mounted on said stud extension, one of said rolls having operative engagement. at all times with one of. said cam members and the other cam roll having at all times operative. engagement with the other of said cam members.

In testimony whereof I aflix my signature. I

CASPER MEHLUM. 

